In general, blood glucose level is used as an index for controlling diabetes, and the blood glucose level approaching a normal value indicates a good control of the blood glucose. Related blood glucose measurement techniques such as those disclosed in R.O.C. Pat. No. M384315 entitled “Non-Invasive Optical Blood Glucose Detector”, R.O.C. Pat. No. 1295566 entitled “Blood Glucose Detection Instrument with Blood Collection Gun, or U.S. Pat. Publication No. 2009/0292186 entitled “Method and System for Non-Invasive Optical Blood Glucose Detection Utilizing Spectral Data Analysis” measure the blood glucose level in blood directly.
However, the blood glucose varies with time and diet significantly, and the blood glucose measurement just indicates the blood glucose value at the time of the measurement only, so that such measurement of the blood glucose level cannot be used solely as an the absolute diabetic control index.
In the red blood cell of a regular person, the percentage of hemoglobin (Hb) is over 95%. If a human body loses control of insulin, a large quantity of glucose will be released from the blood, and the glucose in the blood will be combined slowly with the Hb to form glycosylated hemoglobin (HbA1C). Since the process of forming HbA1C is slow, it takes time to form and accumulate HbA1C, so that the level of HbA1C relates to the daily average blood glucose concentration and does not change immediately with the blood glucose concentration before or after meals, and the blood glucose level measured after meals will not have a big difference. Based on the extent of combining glucose and Hb, World Health Organization (WHO) points out that if the glycosylated hemoglobin of a person occupies more than 6.5% of the total quantity of hemoglobin, the person is considered as a diabetic patient.
In recent years, the measurement of HbA1C content is used extensively for monitoring an average blood glucose level of the diabetic patient. In addition, the red blood cell has a life of approximately 3 months, so that the blood glucose control condition obtained by taking the HbA1C content approximately three months ago can be used for monitoring and controlling the blood glucose condition and serving as a basis for adjusting dosage. According to the estimation made by the International Diabetes Federation, the world's population of diabetic patients is approximately equal to two hundred millions and expected to be over three hundred millions by 2025. Obviously, the detection of HbA1C is a huge business opportunity that is worth for R&D investments, and a quick and convenient HbA1C detection technique can help diabetic patients to control their blood glucose level and reduce the occurrence of complications.
As to the related HbA1C detection techniques, “Method and apparatus for rapid measurement of HbA1C” as disclosed in U.S. Pat. No. 6,582,964 adopts an optical inspection method; “Method of measuring HbA1C” as disclosed in U.S. Pat. Publication No. US2010/0178659 adopts an enzyme detection method; and other methods adopting an electrochemical measurement method, wherein there are two types of electrochemical measurement methods, respectively: DC electrochemical measurement method and AC electrochemical measurement method. As to biosensors, the AC measurement such as the “Systems and methods for replacing signal artifacts in a glucose sensor data stream” disclosed in U.S. Pat. No. 7,998,017 is usually adopted. The AC measurement method mainly uses a cyclic voltammetry, but the electron transfer of the inspecting electrodes will be reduced after the conductivity at the surface of the inspecting electrodes is decreased and the surface is modified. Now, the cyclic voltammetry cannot measure the inspecting electrodes and an object to be tested properly.
The AC impedance measurement method can overcome the aforementioned shortcoming, and thus an AC impedance glycosylated protein measurement such as the “Device for measuring proteins using biosensor” as disclosed in U.S. Pat. No. 2011/0123399 was introduced.
Further, AC stimulation such as the “Method for treatment of diabetes by electrostimulation” as disclosed in U.S. Pat. No. US 2009/0254133 is used as a technical measure for treating diabetes, and this method discloses an AC stimulation with a frequency between 0.00065 Hz and 0.00085 Hz and an ampere between 20 mA and 1 atto (10 A˜18 A) for treating and controlling insulin to stabilize the blood glucose of insulin dependent diabetic patients.